# A bound on Planck-scale deformations of CPT from muon lifetime

## TL;DR

This paper derives an experimental bound on Planck-scale deformations of CPT symmetry using muon lifetime measurements, linking quantum gravity effects to observable particle physics phenomena.

## Contribution

It provides the first quantitative bound on the deformation parameter of the kappa-Poincare algebra from collider data, connecting quantum gravity models to experimental tests.

## Key findings

- Bound on deformation parameter kappa > 4x10^14 GeV from LHC data
- Potential to improve bound to > 2x10^16 GeV with FCC measurements
- Demonstrates observable consequences of Planck-scale CPT deformations

## Abstract

We show that deformed relativistic kinematics, expected to emerge in a flat-spacetime limit of quantum gravity, predicts different lifetimes for particles and their antiparticles. This phenomenon is a consequence of Planck-scale modifications of the action of discrete symmetries. In particular we focus on deformations of the action of CPT derived from the kappa-Poincare algebra, the most studied example of Planck-scale deformation of relativistic symmetries. Looking at lifetimes of muons and anti-muons we are able to derive an experimental bound on the deformation parameter of kappa > 4x10^14 GeV from measurements at the LHC. Such bound has the potential to reach the value of kappa > 2x10^16 GeV using measurements at the planned Future Circular Collider (FCC).